双联熔炼批量生产铸态QT550-7球铁件  

Batch Production of As-Cast QT550-7 Grade Nodular Iron Castings by Using Duplex Melting

作　　者：柳靖 张平 

机构地区：[1]河南广瑞汽车部件股份有限公司,河南新乡453600

出　　处：《现代铸铁》2014年第5期19-21,共3页Modern Cast Iron

摘　　要：介绍了重卡后桥壳的铸件结构及技术要求,详细阐述了铸件的生产过程：为获得比例恰当的铁素体＋珠光体混合基体组织,铸件终成分控制范围为：w（C）3.5%~3.8%,w（Si）0.9%~1.2%,w（Mn）≤0.3%,w（P）〈0.6%,w（S）〈0.05%;采用冲天炉-电炉双联熔炼原铁液;冲天炉铁液经脱S后转入感应炉升温;选用低RE球化剂,采用冲入法进行球化处理;采用75SiFe孕育剂进行包内孕育,同时添加含少量Sb的孕育剂;浇注时用细颗粒75SiFe进行随流孕育。生产结果表明：铸态力学性能超过国家QT550-7标准,符合客户要求。Casting configuration of heavy truck rear bridge housing was introduced and the casting production process was described in detail：in order to obtain mixed matrix structure with proper ferrite pearlite ratio,the final composition of the casting was controlled in the range of w（C）3.5%~3.8%,w（Si）0.9%~1.2%,w（Mn）≤0.3%,w（P）〈0.6%,w（S）〈0.05%;using cupola-induction furnace duplex for melting of the base iron;the cupola iron melt was desulfurized and then reladled into the induction furnace to increase temperature;using low RE content nodularzing alloy and using pour-over process to conduct nodularizing treatment;using 75 SiFe inoculant to conduct ladle inoculation and,at the same time,adding Sb-containing inoculant;using fine grain 75 SiFe to conduct pouring stream inoculation. As the production result,the as-cast mechanical properties exceeded QT550-7 grade standard of the China national standard and met the clients’ requirements.

关 键 词：球墨铸铁 双联熔炼 力学性能 化学成分 

分 类 号：TG255[金属学及工艺—铸造]